1. Field of the Invention
The present invention relates to integrated circuits and more particularly to circuits employing complementary metal oxide semiconductors. More specifically, the present invention pertains to circuits exhibiting hysteresis such that the output switches between high and low voltage levels in response to input voltage causing the switching to occur in a first direction at an input voltage which differs from the voltage causing switching in the opposite direction by an incremental hysteresis voltage.
2. Description of the Prior Art
Hysteresis circuits of various types are well known in the prior art. An example of such prior art is U.S. Pat. No. 3,904,888 which shows a circuit exhibiting hysteresis using transistors of complementary conductivity types. A disadvantage of such prior art is that the differential amplifier input switching point cannot be precisely controlled and is highly variable.